Here is the full list of all 26 Hitman 2: Silent Assassin trophies - there are 5 bronze, 15 silver, 5 gold and 1 platinum.
Unlock all trophies
A mission has been completed with precisely 47 kills
Kill 18 people using the golf club
Kill using all three Knives: Scalpel, Kitchen and Combat Knife
All Shotguns collected and displayed in Hideout
All Firearms collected and displayed in Hideout
All Heavy Weapons collected and displayed in Hideout
All Sniper Rifles collected and displayed in Hideout
All Machine Guns collected and displayed in Hideout
All Melee Weapons collected and displayed in Hideout
Obtain katana from a ninja
Completed normal difficulty
Completed expert difficulty
Completed professional difficulty
All Hand Guns collected and displayed in Hideout
Kill using the fire axe
All Assault Rifles collected and displayed in Hideout
5 Silent Assassin ratings awarded on the Normal difficulty
5 Silent Assassin ratings awarded on the Expert difficulty
5 Silent Assassin ratings awarded on the Professional difficulty
A Silent Assassin rating has been awarded
You completed the first mission on any level
Successfully used anesthetic
A successful headshot has been performed
An innocent person has been killed
A successful kill has been performed